Department of Psychiatry, University of Virginia, Charlottesville, VA, USA.

8

Department of Pharmaceutical Care and Health Systems, University of Minnesota, Minneapolis, MN, USA.

9

Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Medical Ethics and Health Policy, University of Pennsylvania, Philadelphia, PA, USA; Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.

Abstract

Unexpected cognitive lucidity and communication in patients with severe dementias, especially around the time of death, have been observed and reported anecdotally. Here, we review what is known about this phenomenon, related phenomena that provide insight into potential mechanisms, ethical implications, and methodologic considerations for systematic investigation. We conclude that paradoxical lucidity, if systematically confirmed, challenges current assumptions and highlights the possibility of network-level return of cognitive function in cases of severe dementias, which can provide insight into both underlying neurobiology and future therapeutic possibilities.